Manufacture of fiber products



Patented July 31, 1934 UNITED STATES 1,968,418 MANUEACTURE OF FIBER PRODUCTS Treadway B. Munroe and Marion D. @oulter, Chicago, ill.

No Drawing. Application (Dctober 30, 1930, Serial No. 492,359

'1 Claims.

in the manufacture of paper, fiber board, molded fiber products, fiber insulation board, various types of felts such as roofing felt, and in the manufacture of many more or less similar products a it is common to incorporate thereinto, in the process of manufacture, various water-proofing, fire-proofing, insect-repellent, insect toxic, fungicidal, and like substances hereinafter referred to as proofing agents. This invention is directed to 3c the method of incorporating the above-mentioned substances into the fiber product during its process of manufacture.

i'he particular object of this invention is to provide a new manner of procedure'in the manufacture of products such as above named, whereby such treatment as is desired may be applied more readily, more economically, and more uniformly than is accomplished by present practices.

As an example of the application of the principles of this invention, the process will be particularly described in connection with a treatment employed to render fiber insulation board insect,

and fungi-proof. A well known fiber insulation board is manufactured with a major percentage of bagasse fiber and a minor percentage of wood fiber pulp, which latter portion may conveniently be added as pulped newspaper.

The board is formed from a water suspension of the fiber content of close to 0.75%. According to present practice, processes for the inclusion of treatments to incorporate materials such as insecticides and fungicides have comprehended the addition of the necessary chemicals or materials at a point at which the stock is termed half stock, that is, at a point where all the fiber is in suspension, but where it has not been given the final dilution, and at which point the consistency is ordinarily about 1 to 2%, or even slightly higher. As distinguished from past praccide and insecticide to the pulped news print prior to the addition thereof to the primary fiber, various important advantages are obtained.

Some of the advantages of this improved process of treatment are in that the pulped news print is used in a quantity approximately only one-third that of the primary fiber. The fiber derived from the news print is more readily hydrated than the primary fiber and, as hydrated fiber, it exposes a large surface whereby adsorption is increased. Other advantages are that news print is pulped and handled at relatively high consistency-that is, at about 4 to 5%and therefore, due to the smaller amount and the tice, it has been found that by adding the fungihigher consistency, the desired treatment may be more uniformly applied. With the treatment applied initially to a minor portion of the stock, losses are smaller in that a closed system may be maintained, or even if a closed system not used, losses are much reduced due to the fact that the quantity of water in this stock is much less than the quantity of water present after the major and minor portions of fiber have been mixed and diluted to half stock.

In treating an insulating board comprising, roughly, bagasse and 25% pulped news print, the procedure is as follows: I

The pulped news print at a rather high consistency-about i to 5%-has added thereto an appropriate amount of ferric chloride and arsenious acid, say about 3 based on the dry weight of the fiber, with a ratio of As Fe of about lV 1. The pH is then adjusted to the appropriate point between pH 4.0 and pH 12.0, 75 dependent upon the presence of electrolytes, etc.,- to cause a change of the ferric chloride to hydrous ferric oxide which is adsorbed by the fiber and which in turn adsorbs the arsenic, whereby the arsenic is adhered to the fibera The pulped news print with its adhered arsenic is then thoroughly mixed with the bagasse fiber in proportions of about one to three, diluted to proper consistency. for board formation, and then formed into the desired board on an appropriate board-forming machine.

The general scheme of this invention is applicable in any use wherein it is possible to apply it to a portion of the total fiber used, and particularly where it can be applied to the finer and no more highly hydrated, fiber of the furnish.

The principles are applicable in any case wherein the treatment is accomplished by adsorption by the fiber, or precipitation on the fiber; It may be employed in connection with waterproofing, since in products of the type involved the waterproofness is obtained by the aggregate of many particles lying on or between fibers rather than from films formed around individual fibers, and in fireproofing the protection is afforded by uniform distribution of the fireproofing materials rather than by what might be termed integral distribution, considered as mass treatment of all the elements, but which due to dlfliculties of treatment may not comprise m5 uniform treatment.

Whereas the treatment has been described for one particular application, theprinciples are applicable in sizing, for example, with rosin and alum, wax, etc., and in fireproofing with ferrous no oxalate formed as by interaction of ferrous sulphoto and oxalic acid, or in fact, the process is applicable for any treatment of the general type of those particularly mentioned. In the claims the word proofing is employed particularly to designate treatment oi the fiber with on local; and fungi toxic substance.

It is obvious that those skilled in the ert my vary the details oi? construction as well as the steps constituting the method without deport= ing from the spirit oi the invention, and tliere= fore it is not desired to be limited to the foregoing except as may be required by the claims:

What is claimed is:-- Y

1. The method of proofing o, fibrous product which consists in adding to e Erection thereof ferric chloride and orsenious acid, and then colmixing sold fraction with the remainder of the fibrous materiel to form said product.

2. A fiber product of the type desiailoed comprising o fiber portion carrying on adhered proof= ing agent and integrally incorporated throughout the primory fiber comprising'the product, and. wherein the adhered proofing agent is o complex arsenicelresulting from uiterection of ferric chloride and erseiiioos acid in dilute solution.

3. A fiber product oi the type described com prising o fiber portion coming on adhered proofing scent and integrally incoroted throiiggh out the primary fiber comprising the product, and wherein the adhered proofing agent comprises arsenious acid as an element of a. substantially A cold water insoluble colloidal complem 4. The method of proofing a fibrous product which consists in adding to a fraction thereof on adherent arsenical and subsequently admixing said fraction with the remainder of the fibrous material to form said prooied product.

5. A fiber product of the type described, com prising e fiber portion carrying an adherent proofing agent and integrally incorporated throughout the primary fiber comprising the product and wherein the adherent proofing agent comprises ersenious acid as an element thereoi'.

ii. A fiber product having a primary fiber con= tent and a. secondary fiber content, the secondary fiber content carrying on insect and fungi toxic chemical and integrally distributed throughout the primary fiber contents thereof.

' l. A fiber product having o primary fiber con tent end a secondary fiber content, the secondary fiber content carrying at substantially water in? soluble adhered insect and iungi toxic arsenicel, the secondary fiber content integrally distributed throughout the primary fiber content.

TREADWAY 1B. MUNRQE.

@N D. comm.

lllll llll ire 

